A flat gasket of this kind is known from DE 100 37 964 A1, for example.
The elastomeric sealing element may in particular be disposed where a step is located in one of the component sealing faces which are pressed against the flat gasket when the flat gasket is in the fitted, pressed state.
If the flat gasket is a cylinder head gasket with a chain case sealing region, a step of this kind occurs in at least one of the component sealing faces which is adjacent to the cylinder head gasket, in particular in the region of a joint between the engine block and a chain case lower part which is adjacent to the engine block and/or at a joint between the cylinder head and a chain case upper part which is adjacent to the cylinder head.
In order to obtain at a step of this kind a reliable seal by means of an elastomeric sealing element which crosses the step, on the one hand sufficient sealing material must be made available so that a sealing bead of a sufficient height is formed upon mounting the cylinder head gasket and subsequent curing (e.g. at the operating temperature of the engine or a lower temperature which is raised with respect to room temperature). On the other hand there should also not be too much sealing material, as excess sealing material may run in between the gasket layers of the cylinder head gasket and/or between the cylinder head gasket and the component sealing faces and be cured here when the cylinder head gasket is mounted, whereby the individual gasket layers of the cylinder head gasket or the component sealing faces and the outer main faces of the cylinder head gasket are undesirably held at a spacing from one another.
As the height of the step in the component sealing face is subject to considerable fluctuation on account of the manufacturing and mounting tolerances, it is therefore difficult to select the optimum quantity of sealing material for forming the elastomeric sealing element.